Near Earth Asteroid Buzz


Post 1,002 finds me pondering a near Earth asteroid. Not one of the 1,634 potentially hazardous objects currently identified and monitored by science – my thoughts are with 2015 VY105. Less than a day after discovery on November 14, VY105 passed over the Pacific Ocean at a distance of 34,000 Km. Trust me – that’s close.

Undetected until a few hours before passing, closer than many Earth orbiting satellites, traveling at an estimated speed of 62,000 km/h, we were never in danger. At 3 – 9 meters, VY105 wasn’t big enough to cause trouble. Even if it spanked our atmosphere, an asteroid that size would disintegrate before impact. Witnesses to a hypothetical demise, might have been rewarded with an outstanding fireball.

In October 2008, asteroid 2008 TC3 pulled a similar stunt. 19 hours after detection TC3 entered our atmosphere over the Sudan. Estimated at 4 meters, it vaporized long before hints of calamity. Small doesn’t necessarily mean harmless – in February 2013, a fireball and explosion over Chelyabinsk in Russia’s Ural mountains, blew out windows, injuring over 1,000 people. Undetected, this meteor wasn’t named, no impact crater was found. Science believes damage from an estimated 15 meter asteroid occurred when it exploded 15-20 Km above ground. Entering the atmosphere at a shallow 20 degree angle, it blazed across the horizon at over 62,000 km/h disintegrating at low altitude with the force of 300 kilotons TNT.

Asteroid Explodes Near Chelyabinsk, Russia on Feb. 15 2013

The asteroid that exploded near Chelyabinsk, Russia on Feb. 15, 2013 has provided scientists new insights into the risks of smaller asteroid impacts. This 3D simulation of the Chelyabinsk meteor explosion by Mark Boslough was rendered by Brad Carvey using the CTH code on Sandia National Laboratories’ Red Sky supercomputer. Andrea Carvey composited the wireframe tail. Photo by Olga Kruglova. Credit – Sandia National Laboratories.

http://www.space.com/24714-russian-meteor-blast-chelyabinsk-anniversary.html?li_source=LI&li_medium=most-popular

Rather than criticizing astronomers over a few missed space rocks – plant seeds of collective determination to properly fund science. Cosmic science encompasses far more than raising a flag on Mars. Every satellite, probe, telescope and innovation takes us closer to solving the dilemma of rogue asteroids. VY105 managed to buzz Earth hours after making itself known – we have to do better than that.

http://earthsky.org/space/asteroid-2015-vy105-buzzed-earth-this-weekend-hours-after-discovery?utm_source=EarthSky+News&utm_campaign=0e426be346-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-0e426be346-393970565

 

 

 

Asteroid 2014 YB35


On Friday March 27, asteroid 2014 YB35 passes our planet at a distance of nearly four and a half million Kilometers. No small rock, YB35’s estimated girth of 750 meters or so, likely accounts for news stories and internet chatter of “NASA on high alert” and “near miss” hysteria.

http://www.inquisitr.com/1954895/nasa-on-alert-as-huge-asteroid-2014-yb35-set-to-make-close-earth-approach-at-23000-mph-on-friday/

As of today, 1563 such objects grace the PHA (Potentially Hazardous Asteroid) roster. A PHA is any space object orbiting within 100 LD (1 Lunar Distance being the distance between Earth and the Moon) and large enough to make it through our atmosphere. 2014 YB35 will pass at 11.6 LD.

I’ve spent the last while pondering why sporadic asteroid buzz annoys me so much. As someone who pays attention to these things, a person devoting countless hours and energy in hope others start paying attention – reality dictates most won’t give it a second thought after Friday. The 1908 Tunguska event over Siberia – 2000 square Kilometers of forest obliterated by a asteroid estimated at 50 meters across, one that vaporized without making impact. Pondering Tunguska makes me grumpy. Intermittent excitement because something is large – tweeted today, forgotten tomorrow.

In conclusion, relax – 2014 YB35 is more “just another day” than “high alert” at NASA’s office. Statistically speaking, true “high alert” days are unavoidable – no different from catastrophic earthquakes and climate changing volcanic eruptions. Maybe I’m odd, rather than fret about probability in my lifetime or that of my children, I choose to learn all I can with detached interest. Go figure.

Small Asteroid Hits


The Chelyabinsk asteroid over Russia on February 15, 2013 was a “small asteroid” estimated at 20 meters across. Small, yet credited with shattering windows in 7,200 buildings over 6 cities, and injuring 1,500 people.

On November 14, 2014 NASA released a map produced by the Near Earth Object (NEO) program showing 556 small asteroid atmosphere “hits” from 1994-2013. Almost all of them “burned up”, and were classified as “fireballs”. Fireballs or bright meteors are known by the term “bolide”. The map below illustrates bolide events as universal – the orange dots are day, and blue night. Size difference in dots pertain to “optical radiant energy”. I’m no scientist, and fear my explanation of the term might fall flat – the link below is helpful in that respect.

NASA announced the Asteroid Redirect Mission (ARM) in June 2014, a ambitious program aimed to identify, capture, and redirect potentially hazardous asteroids to an orbit around the Moon. See link below…

http://www.nasa.gov/content/what-is-nasa-s-asteroid-redirect-mission/#.VGxaxMlflLM

On a grander scale, all objects greater than 100 meters and orbiting or likely to orbit Earth within 100 Lunar Distance (LD) – 1 LD being the distance from Earth to the Moon, are called Potentially Hazardous Asteroids (PHA) – as of today 1512 of these objects are being monitored.

http://earthsky.org/space/heres-how-often-small-asteroids-enter-earths-atmosphere?utm_source=EarthSky+News&utm_campaign=faa7fe7c5f-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-faa7fe7c5f-393970565

 View larger | Sizes of red dots (daytime impacts) and blue dots (nighttime impacts) are proportional to the optical radiated energy of impacts measured in billions of Joules (GJ) of energy, and show the location of impacts from objects about 1 meter (3 feet) to almost 20 meters (60 feet) in size. Image credit: Planetary Science

View larger | Bolide events, 1994-2013. A bolide is what most people would call a fireball or very bright meteor. Map shows location of atmospheric impacts from small asteroids about 1 meter (3 feet) to almost 20 meters (60 feet) in size. It shows 556 separate events in a 20-year period. Orange dots indicate daytime events; blue dots indicate nighttime events. Sizes of dots are proportional to the optical radiated energy of events. Image via Planetary Science

Where Did You Come From 2014 AA?


It’s no secret I check space weather every day; solar wind, chance of flares, active sun spots, list of PHA (potentially harmful asteroid) in the next few months. My eyes settled on 2014 AA, Jan.2, 2014, .001 LD  (1 LD = the distance from earth to the moon), 3 meters. Holy crap – this wasn’t here yesterday. Where did you come from 2014 AA? It seems I needn’t have bothered trying to calculate what .001 of 384,000 Kms. was, 2014 AA entered our atmosphere around midnight EST. Believed to have burned up over the Atlantic, somewhere off the east coast of Africa.

This rogue little space rock hadn’t even been discovered until New Years Day, 24 hours later it slams into our atmosphere. Another nugget of information presented itself – this is only the second time astronomers spotted an asteroid before it hit our atmosphere. The first time in 2008 when 2008 TC3 burned up over the Sudan, and coincidentally TC 3 wasn’t discovered until the day before impact.

http://earthsky.org/earth/small-asteroid-entered-our-atmosphere-just-hours-ago

There isn’t a lot any of us can do about falling space junk; I’m not pacing the floor, fretting about a doomsday asteroid. There isn’t much we could do about a sudden, unexpected projectile hurtling towards our planet. That said, I was truly shocked to learn only two asteroids have ever been detected before hitting our atmosphere. Currently spaceweather lists 1488 PHA’s ranging from a few meters to Km’s in width. Gravity and its pull, orbits, and trajectories are fickle, I’d be a much happier ponderer if we put a little more effort into more than 24 hours notice.

Image – skyandtelescope.com